impl/src/main/java/org/apache/myfaces/view/facelets/TemplateContext.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.myfaces.view.facelets;

import java.io.IOException;
import java.util.Map;
import java.util.Set;

import javax.el.ELException;
import javax.el.ValueExpression;
import javax.faces.FacesException;
import javax.faces.component.UIComponent;
import javax.faces.view.facelets.Facelet;
import javax.faces.view.facelets.FaceletContext;
import javax.faces.view.facelets.FaceletException;

/**
 * This class is used to encapsulate the information required to resolve
 * facelets templates.
 * 
 * Composite components require to "isolate" the inner template resolution.
 * That means, when a ui:xx tag is used, do not take into account the outer
 * templates defined.
 * 
 * The methods here are only used by the current implementation and the intention
 * is not expose it as public api.
 * 
 * @author Leonardo Uribe (latest modification by $Author$)
 * @version $Revision$ $Date$
 * @since 2.0.1
 */
public abstract class TemplateContext
{
    /**
     * Pop the last added pushed TemplateClient
     * @see TemplateClient
     */
    public abstract TemplateManager popClient(final AbstractFaceletContext actx);
    
    /**
     * Push the passed TemplateClient onto the stack for Definition Resolution
     * @param client
     * @see TemplateClient
     */
    public abstract void pushClient(final AbstractFaceletContext actx, final AbstractFacelet owner,
                                    final TemplateClient client);
    
    /**
     * Pop the last added extended TemplateClient
     * @param actx
     */
    public abstract TemplateManager popExtendedClient(final AbstractFaceletContext actx);
    
    public abstract void extendClient(final AbstractFaceletContext actx, final AbstractFacelet owner,
                                      final TemplateClient client);
    
    /**
     * This method will walk through the TemplateClient stack to resolve and
     * apply the definition for the passed name.
     * If it's been resolved and applied, this method will return true.
     * 
     * @param parent the UIComponent to apply to
     * @param name name or null of the definition you want to apply
     * @return true if successfully applied, otherwise false
     * @throws IOException
     * @throws FaceletException
     * @throws FacesException
     * @throws ELException
     */
    public abstract boolean includeDefinition(FaceletContext ctx, Facelet owner, UIComponent parent, String name)
            throws IOException, FaceletException, FacesException, ELException;
    
    public abstract TemplateManager getCompositeComponentClient();

    /**
     * Set the composite component TemplateManager instance, used to resolve
     * cc:insertChildred or cc:insertFacet usages for the current template
     * context 
     */
    public abstract void setCompositeComponentClient(TemplateManager compositeComponentClient);

    /**
     * Return the param value expression associated to the key passed,
     * preserving the precedence of each template client. 
     * 
     * @since 2.0.8
     * @param key
     * @return
     */
    public abstract ValueExpression getParameter(String key);
    
    /**
     * Associate the param to the latest template client.
     * 
     * @since 2.0.8
     * @param key
     */
    public abstract void setParameter(String key, ValueExpression value);
    
    /**
     * Check if no parameters are set.
     * 
     * @since 2.0.8
     * @return
     */
    public abstract boolean isParameterEmpty();
    
    /**
     * 
     * @since 2.0.8
     * @return
     */
    public abstract Map<String, ValueExpression> getParameterMap();

    /**
     * 
     * @since 2.0.8
     * @return
     */
    public abstract boolean isAllowCacheELExpressions();

    /**
     * 
     * @since 2.0.8
     */
    public abstract void setAllowCacheELExpressions(boolean cacheELExpressions);
    
    /**
     * 
     * @since 2.1.12
     * @param key
     * @return 
     */
    public abstract boolean containsParameter(String key);
    
    /**
     * Return a set of the parameters known associated to this template context and/or
     * template. This logic is used to detect which EL Expressions can be cached or not.
     * 
     * @since 2.1.12
     * @return 
     */
    public abstract Set<String> getKnownParameters();
    
    /**
     * 
     * @since 2.1.12
     * @param key
     * @return 
     */
    public abstract boolean containsKnownParameter(String key);
    
    /**
     * 
     * @since 2.1.12
     * @return 
     */
    public abstract boolean isKnownParametersEmpty();
    
    /**
     * 
     * @since 2.1.12
     * @param knownParameters 
     */
    public abstract void addKnownParameters(String knownParameters);
}